Prefer sysfs for USB host devices

Scanning for devices via /sys/bus/usb/devices/ and using them via the
/dev/bus/usb/<bus>/<device> character devices is the prefered method
on modern kernels, so try that first.

When using SELinux and libvirt, qemu will have access to /sys/bus/usb
but not /proc/bus/usb, so although the current code will work just
fine, it will generate SELinux AVC warnings.

See also:

  https://bugzilla.redhat.com/508326

Reported-by: Daniel Berrange <berrange@redhat.com>
Signed-off-by: Mark McLoughlin <markmc@redhat.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
This commit is contained in:
Mark McLoughlin 2009-07-03 09:28:02 +01:00 committed by Anthony Liguori
parent 1fa63e43e6
commit 554962405c

View File

@ -1265,6 +1265,15 @@ static int usb_host_scan(void *opaque, USBScanFunc *func)
/* only check the host once */
if (!usb_fs_type) {
dir = opendir(USBSYSBUS_PATH "/devices");
if (dir) {
/* devices found in /dev/bus/usb/ (yes - not a mistake!) */
strcpy(devpath, USBDEVBUS_PATH);
usb_fs_type = USB_FS_SYS;
closedir(dir);
dprintf(USBDBG_DEVOPENED, USBSYSBUS_PATH);
goto found_devices;
}
f = fopen(USBPROCBUS_PATH "/devices", "r");
if (f) {
/* devices found in /proc/bus/usb/ */
@ -1284,15 +1293,6 @@ static int usb_host_scan(void *opaque, USBScanFunc *func)
dprintf(USBDBG_DEVOPENED, USBDEVBUS_PATH);
goto found_devices;
}
dir = opendir(USBSYSBUS_PATH "/devices");
if (dir) {
/* devices found in /dev/bus/usb/ (yes - not a mistake!) */
strcpy(devpath, USBDEVBUS_PATH);
usb_fs_type = USB_FS_SYS;
closedir(dir);
dprintf(USBDBG_DEVOPENED, USBSYSBUS_PATH);
goto found_devices;
}
found_devices:
if (!usb_fs_type) {
monitor_printf(mon, "husb: unable to access USB devices\n");